aw11 O2 sensors

[DBoy]

My aw11 engine light is always on. I checked the error codes and it returned an error number 42 which is Oxygen Sensor signal error. Now i had a look at the O2 sensor on the car and it looks like it was recently changed, in fact i think i remember the guy who i bought it off saying something about it being changed recently. The one thats on the car is a 3 wire sensor, but when i was looking around on eBay there was one that said it was for a aw11 but it was a 1 wire sensor. What type is it supposed to have? its a late 1987 Australian delivered NA aw11.

[TooF]

ive got an odd feeling they are only a single wire unit.

[Dale]

I'd imagine a single wire or a 4 wire sensor, can you see the plug that it's meant to go into?

[oldcorollas]

single and 3 wire are the same.. except the 3 wire has a heater.

perhaps it was hooked up incorrectly?

the two same coloured wires are usually the heater. one goes to ign switched power, and the other is earth.

the different coloured wire is the signal wire, that goes to the ECU.

you can easily check which is which with multimeter

[DaveW]

both my NA and SC 86's run a single wire

[DBoy]

hmm, well since they updated the aw11 in late 87, i guess they might have changed it to a 3 wire one or something. I've just been thinking about it some more. Would it even be possible to put the wrong o2 sensor in? are the plugs different?

[Dale]

Just had look in the EPC, they use the same part number for all early and late model AW11s, looks like single wire to me!

[Devils]

They normally use single wire sensors in N/A and heated sensors in blown motors.

Unless there was also an ECU revision between models then it would be a safe guess that they are the same 'type' throughout as only a few manufacturers tried the two different types of O2 sensors (Titania and Zirconia), but when they did this they also revised the ECU and usually something else on the engine as well.

Pull it out and check that it's not sooted up, as that code will come up even if the sensor is 'slow to react', i.e. the voltage stays the same for more than a second (or less).

[feral4mr2]

the aw11 4agze runs a single wire 02 sensor, as mentioned above i know the later 4age uses a 4 wire.

i would also look into oldcorolla's suggestion, if yours runs a single wire and a 3 wire has been used, then it could well be wired to the incorrect wire on the sensor.